It has been reported that ethylenically unsaturated monomers can be grafted onto mineral oil. U.S. Pat. No. 4,195,008 discloses such a process in the preparation of a carpet backing. It is also reported in U.S. Pat. No. 3,272,746 that in the preparation of ashless dispersants by the reaction of a hydrocarbon-substituted succinic anhydride with an amine that highly refined saturated white oils can be used as the hydrocarbon substituent. U.S. Pat. No. 4,089,794 describes the reaction of maleic anhydride with olefin polymer in a mineral oil solvent. It is noted that some of the maleic anhydride can react with the mineral oil.
Most commercial ashless dispersants are made by reacting maleic anhydride with a high molecular weight olefin polymer such as polyisobutylene followed by reaction with an amine to form amide or imide groups. It has also been reported that useful dispersants can be made by co-grafting alkyl acrylates or methacrylates and maleic anhydride onto an ethylene/propylene copolymer (U.S. Pat. No. 4,160,739).